Lactam polymerization initiators

ABSTRACT

Disclosed are lactam polymerization initiators comprising at least two lactam terminal groups of the formula: ##STR1## wherein Q is a lactam residue containing a C 3  to C 11  alkylene group and is bonded to a carbonyl through the nitrogen atom of the lactam; A is an aliphatic or aromatic hydrocarbyl or hydrocarbyl ether group; m is 0 or 1; when m is 0, n is 0 or 1 and p is 1; when m is 1, n is in the range of 1 to 3 and p=n; and an elastomeric backbone derived from a telechelic polyamine containing at least two primary or secondary amine groups. Also disclosed are a process for forming the same; nylon block copolymers produced therefrom; and a process for the polymerization thereof.

This is a division of application Ser. No. 838,643, filed Mar. 11, 1986.

The present invention relates to lactam polymerization initiators, to aprocess for forming the same, to nylon block copolymers producedtherefrom, and to a process for polymerization thereof.

Polymers containing polyamide segments and segments of another materialhave been disclosed in the art and are herein referred to as "nylonblock copolymers". A combination of polyamide segments and segments ofanother polymeric material allows for the obtaining of block copolymerswith unique combinations of properties. The properties can be varied byvarying the polyamide and/or other polymeric segments in the blockcopolymer. Particularly useful are those block copolymers which containalternating hard and soft segments. The hard segments (i.e., T_(g) orT_(m) above room temperature) provide thermoplasticity and the softsegments (i.e., T_(g) below room temperature) provide elastomericbehavior; and, in combination, the alternating hard and soft segmentsprovide toughened rigid systems suitable for use in the manufacture offibers, fabrics, films and molding resins.

In U.S. Pat. Nos. 4,031,164, issued June 21, 1977, and 4,223,112, issuedSept. 16, 1980, both to Hedrick and Gabbert, there are taught nylonblock copolymers containing nylon segments derived from lactam monomersand other polymeric blocks derived from polyols. Polyacyllactams providelinkages for the blocks in the nylon block copolymers taught therein.The Hedrick and Gabbert patents teach that the preparation of theirblock copolymers involves mixing together lactam monomer, polyol, lactampolymerization catalyst and the polyacyllactam. The process typicallyresults in the formation of some polyamide homopolymer due to thepolyacyllactams which are acyllactam containing materials, ashereinafter defined, reacting solely with lactam monomer. It ispreferable to minimize the formation of homopolymer since it generallycauses detrimental effects such as the reduction of impact properties ofthe molded nylon block copolymer.

A catalytic process for imide-alcohol condensation taught by Hedrick andGabbert in U.S. Pat. No. Re 30,371, reissued Aug. 12, 1980, can beemployed in the preparation of the Hedrick and Gabbert nylon blockcopolymers. Reacting a polyol and polyacyllactam in accordance with thisprocess results in a mixture containing residual catalyst that mayadvantageously be removed or inactivated to reduce the potentialdifficulties in any subsequent preparation of nylon block copolymermoldings from said mixture.

Copending application, Ser. No. 467,626, now U.S. Pat. No. 4,581,419,issued Apr. 8, 1986, discloses lactam polymerization initiators,referred to as acyllactam functional materials, useful for preparingnylon block copolymers, which are formed in two steps by reacting ahydroxyl-containing material with an acid halide functional materialcontaining two or more carboxylic acid halide groups to form a secondacid halide functionalized material and then by reacting the second acidhalide functional material with a lactam monomer to provide terminallactam initiator groups. Such lactam polymerization initiators have thegeneral formula: ##STR2## wherein Q is a lactam residue bonded to acarbonyl through the nitrogen atom of the lactam and has the structuralformula: ##STR3## Y is a C₃ -C₁₁ alkylene group; a is 1, 2 or 3; b is 2or more; R is a di- or a polyvalent group selected from hydrocarbongroups and hydrocarbon groups containing ether linkages; and Z is asegment of a polyether, a polyester containing polyether segments, ahydrocarbon, a polysiloxane, or combinations thereof.

U.S. Pat. No. 4,490,520, issued to Ogasa et al, discloses thepreparation of polyamides from lactam polymerization initiators andω-lactam in the presence of an alkali catalyst. The lactampolymerization initiators are prepared from polyfunctional cocatalysts,e.g. from polyacyllactams, and a polyoxyalkylene amine either prior toor during the polymerization of the ω-lactam.

We have now discovered a method of preparing lactam polymerizationinitiators from amine-functionalized materials, such as thepolyoxyalkylene polyamines, which provide nylon block copolymerspossessing desirable physical properties and containing amide ratherthan ester linkages.

One aspect of the present invention is provided by the lactampolymerization initiators which can be employed in the preparation ofnylon block copolymers. Another aspect is provided by the use of suchinitiators in the preparation of nylon block copolymers by a very fastreaction pathway, which is particularly useful in reaction injectionmolding processes, providing amide-linked products which are morehydrolytically and thermally stable than those in which the blocks arelinked by ester groups and which have greater impact strength thanamide-linked products prepared by methods disclosed in the art.

Lactam polymerization initiators according to the invention comprise atleast two lactam terminal groups represented by the formula: ##STR4##wherein Q is a lactam residue containing a C₃ to C₁₁ alkylene group,bonded to a carbonyl through the nitrogen atom of the lactam; A is analiphatic or aromatic hydrocarbyl or hydrocarbyl ether group; m is 0 or1, when m is 0, n is 0 or 1 and p is 1, and when m is 1, n is in therange of 1 to 3 and p=n; and an elastomeric backbone derived from atelechelic polyamine containing at least two primary amine groups. Suchinitiators are represented by the formula: ##STR5## wherein Z ispolyvalent radical derived from a telechelic polyamine containing atleast 2 primary amine groups and is selected from the group consistingof polyoxyalkylene polyamines, oxyalkylene copolymer polyamines,polyalkadiene polyamines, alkadiene copolymer polyamines, polyalkenepolyamines, alkene copolymer polyamines, and combinations thereof; t isat least 1; A, Q, m, n, and p are as previously specified or designated.Such initiators can be formed by reaction of an acyllactam monomercontaining at least two acyllactam groups and a telechelic polyamine. Inorder to form a nylon block copolymer with superior properties, at least90 mole %, preferably 95 mole %, of the amine groups of the polyamineshould have been converted to the lactam terminal groups prior to anysubstantial lactam polymerization. Such may be accomplished bypreforming the initiator or forming it in situ prior to exposure tolactam polymerization conditions.

Advantageously, the lactam polymerization initiator has a number averagemolecular weight from about 500 to about 15,000, and preferably, fromabout 1,000 to about 10,000. Preferred lactam polymerization initiatorsare those derived from polyether and polyhydrocarbon polyamines andhaving molecular weights of at least about 1,000 and, preferably, fromabout 2,000 to about 6,000. All references herein to molecular weight,unless otherwise indicated, shall mean number average molecular weightwhich is determined by methods well-known in the art.

Initiators according to the invention may be obtained by performing thefollowing sequential steps which proceed at ambient temperature:

(a) complexing the acid halide groups of a polyfunctional acid halidewith a tertiary amine;

(b) reacting at least one but less than all of the complexed acid halidegroups with a lactam monomer represented by the formula ##STR6## where Yis a C₃ to C₁₁ alkylene group to replace the halogen with lactam residueand form an ammonium halide salt;

(c) reacting at least 90 mole % of the remaining complexed acid halidegroups with a polyfunctional primary amine to form amide groups; and

(d) removing the ammonium halide salt.

Advantageously, the acid halide groups are in slight stoichiometricexcess over the amine groups. In this process the acid halide groupsreact with the amine groups in the polyamine to form an amide linkageand a substituted ammonium halide byproduct. An example of this reactionis as follows: ##STR7## wherein X is chlorine or bromine, :NR₃ is atertiary amine, Z, Q, A, and m are as previously described, and k≧dx. Itis recognized that some polyfunctional acid halide may contain more thanone acid halide group following reaction with the lactam monomer in step(b) to form the initiator. In such a case the polyfunctional acid halidemay couple two or more telechelic polyamines with the elimination of twosubstituted ammonium halide molecules per coupling reaction.

The initiator is advantageously formed in the presence of anon-interfering solvent, e.g. cyclohexane, toluene, tetrahydrofuran, oracetone. It may also be formed at elevated temperatures, e.g. 30° C. to150° C., depending upon the nature of the solvent used. If a solvent isused, it may be removed by distillation following formation of theinitiator.

Advantageously, the telechelic polyamine is of number average molecularweight in the range of about 300 to 10,000, preferably at least 500, andmore preferably 1000, and is selected to provide a backbone of soft,elastomeric segments in the nylon block copolymer while the polylactamsegments produced by addition polymerization of the lactam monomer ontothe initiator provide hard, crystalline segments. Soft segmentscontribute a glass transition temperature, T_(g), of less than about 0°C., preferably less than about -25° C., when they are incorporated intoa nylon block copolymer. The glass transition temperature isconveniently measured by differential scanning calorimetry undernitrogen at a scanning rate of 10°-20° per minute. Such segments areadvantageously derived from telechelic polyamines selected from thegroup consisting of polyoxyalkylene polyamines, oxyalkylene copolymerpolyamines, polyalkadiene polyamines, alkadiene copolymer polyamines,polyalkene polyamines, alkene copolymer polyamines, and combinationsthereof. The amount of elastomeric segments in the nylon blockcopolymers prepared by the process of the present invention can bevaried between 10 and 90 weight percent of the copolymer, depending onthe properties being sought.

Exemplary suitable polymeric hydrocarbon polyamines are polybutadienediamine, polybutadiene polyamines and butadiene-acrylonitrile copolymerpolyamines. Exemplary suitable polyether polyamines arepoly(oxybutylene)diamine, poly(oxyethylene) diamine,poly(oxypropylene)diamine, poly(oxypropylene) triamine,poly(oxypropylene) tetramine, and combinations thereof, for examples,block copolymers of poly(oxypropylene) and poly(oxyethylene)functionalized with at least two amine groups. Preferred polyetherpolyamines are poly(oxypropylene) triamines having a number averagemolecular weight of at least about 5000.

The telechelic polyamine may be formed from a telechelic polyol byreplacing the hydroxyl groups with amine groups according to theprocedures described in U.S. Pat. Nos. 3,155,728 and 3,236,896. Due tothe process for forming these compounds, it is expected that there maybe some residual hydroxyl groups. Alternatively, nitrile-containingpolymers may be amine-functionalized by reduction of the nitrile groups,and formyl-containing polymers may be amine-functionalized byreductively aminating the formyl groups.

Suitable polyfunctional acid halides useful for preparing lactampolymerization initiators are of the formula: ##STR8## wherein m is 0 or1 and when m is 0, n is 0 or 1 and p=1 and when m is 1, n is in therange of 1 to 3 and p=n; and X is chlorine or bromine. Advantageously mand n are 1. A can be any aliphatic or aromatic hydrocarbyl orhydrocarbyl ether group. Preferred A groups are para- and meta-phenyleneand --CH₂ --_(x) wherein x is in the range of 3 to 8; more preferred arepara- and meta-phenylene and mixtures thereof, which yield nylon blockcopolymers with superior physical properties. Another preferred diacidhalide contains the oxalyl radical which results when m=0 and n=1.

Suitable lactams for reacting with the complexed acid halide are thosehaving C₃ to C₁₁ alkylene groups, and preferred, based on theirreactivity and availability, are those having C₃ or C₅ alkylene groups,i.e. 2-pyrrolidinone or ε-caprolactam.

Exemplary of tertiary amines which may be used to complex with thepolyfunctional acid halides are trialkyl amines, pyridine andalkyl-substituted pyridines, quinoline, and other substituted amineswherein the substituents do not substantially interfere with thefunction of the amine as a complexing agent or with the formation of thelactam polymerization initiator. Advantageously the ammonium salt andany excess tertiary amine are removed following formation of theinitiator.

The lactam polymerization initiators are advantageously prepared by thereaction of one equivalent of telechelic polyamine, based on the numberof amine groups, with one equivalent of acid halide, based on the numberof acid halide groups. However, when polymeric lactam polymerizationinitiators with backbones containing alternating hard and soft segmentsare desired, a polyfunctional acid halide may be reacted to link two ormore of the telechelic polyamines. In such a case, the equivalent ratioof telechelic polyamine to acid halide may be selected less than 1:1.For example when the telechelic polyamine is trifunctional and adifunctional acid halide is added to couple two polyamines, anequivalent ratio of 1:3 may be used to advantage to provide an polymerictetrafunctional initiator. The above referred to soft segmentspreferably conform to the molecular weight limitations discussed abovegenerally for the telechelic polyamines.

The lactam polymerization initiator can be reacted with lactam monomer,preferably ε-caprolactam, in the presence of a lactam polymerizationcatalyst to form a nylon block copolymer having soft and hard segments,wherein the hard segments are represented by the formula: ##STR9##wherein q is from about 4 to about 300 and Y is as previously specifiedand wherein the hard and soft segments are linked by amide linkages ofthe formula: ##STR10## wherein A, Y, m, n and p are as previouslyspecified. Such a block copolymer is substantially free of esterlinkages between the hard and soft segments and is more hydrolyticallyand thermally stable than those containing such ester linkages.

The weight average molecular weight of the resulting nylon blockcopolymer may vary widely and is advantageously in the range from about18,000 to about 100,000. The molecular weight is generally dependentupon the molar ratio of lactam monomer and lactam polymerizationinitiator. The concentration of initiator, or activated N-lactam, groupsprovided by the lactam polymerization initiator and present during thepolymerization of lactam monomer will affect the overall reaction rate.The total amount of activated N-lactam groups, i.e. equivalents ofinitiator groups, may be varied by means of the functionality and/or theconcentration of initiator present in the mixture. Generally, thefunctionality, or number of activated N-lactam groups per molecule, ofthe initiator is at least two, preferably from about 2 to about 10, andstill more preferably from about 3 to about 6. Generally, the amount oflactam polymerization initiator used is at least about 0.1 mole percentof the total molar amount of caprolactam monomer used, and morepreferably, from 0.25 to 1.0 mole percent.

When the lactam polymerization initiator is used to prepare nylon-6block copolymers by the reaction with ε-caprolactam monomer in thepresence of a suitable catalyst, the resulting block copolymer isgenerally comprised of the lactam polymerization initiator to which areattached polyamide chains having repeat units of the general structure:##STR11##

While the nylon-6 block copolymer is essentially prepared fromε-caprolactam, other lactam monomers may be included so long as thereaction rate or degree of caprolactam polymerization is notsubstantially impaired.

The lactam polymerization catalyst useful herein includes that class ofcompounds commonly recognized as suitable basic catalysts for theanionic polymerization of lactams. In general, all alkali or alkalineearth metals are effective either in metallic form or in the form ofhydrides, halohydrides, alkylhalides, oxides, hydroxides, carbonates andthe like. Such catalysts are more fully described in U.S. Pat. No.4,031,164. Particularly useful for the lactam polymerization is a C₃ toC₁₁ lactam magnesium halide, preferably derived from lactam selectedfrom the group consisting of ε-caprolactam and 2-pyrrolidinone and morepreferably the catalyst is selected from ε-caprolactam magnesiumbromide, (2-oxo-1-tetrahydroazepinyl magnesium bromide), and2-pyrrolidinone magnesium bromide, (2-oxo-1-pyrrolidinyl magnesiumbromide) The amount of catalyst used is an amount which gives anappreciable rate of polymerization. Advantageously, the amount ofmagnesium lactam polymerization catalyst for the practice of the presentinvention is in the range of 0.3 to 2.0 mole percent based on the totalmolar amount of lactam monomer and, preferably, from about 0.6 to about1.2 mole percent. The reaction rate is dependent upon the concentrationof catalyst being used and other parameters such as the temperature atwhich the reaction is being carried out.

The nylon block copolymer is preferably formed by a reactive fabricationprocess, such as reaction injection molding (RIM) but may also be formedby other conventional methods, such as casting or mass polymerization.

In a preferred method for preparing a nylon block copolymer according tothe invention a first reactant stream of lactam monomer and lactampolymerization initiator and a second reactant stream of lactam andlactam magnesium halide polymerization catalyst are admixed to bringthem into reactive contact at the polymerization temperature, forexample, at a temperature in the range of from about 70° C. to about230° C., preferably from about 90° C. to about 190° C., and morepreferably, about 120° C. to about 160° C. In accordance with aparticular method of preparing a nylon block copolymer, the abovedescribed admixture is immediately introduced into a mold which ismaintained at the polymerization temperature until the lactam monomerhas polymerized. Typically, by selecting a lactam polymerizationinitiator, adjusting the polymerization temperature and/or by adjustingthe amount of lactam magnesium halide polymerization catalyst or lactampolymerization initiator, the lactam monomer polymerization may beinitiated and completed within a relatively short period of time of lessthan 5 minutes. When the lactam polymerization initiator is one of thepresent invention, containing amide rather than ester linkages andformed by the process disclosed herein, the polymerization time may bereduced to less than 3 minutes, preferably less than 1 minute.

The physical properties given for the following examples were obtainedusing tests substantially in accordance with the following procedures:

Standard Exotherm: The reaction rate of lactam monomer polymerization isdetermined from the exotherm of the reaction by the following method: A30 gauge iron constantan thermocouple connected to a recordingpotentiometer, is positioned within a mold. The mold is heated to 140°Celcius (C). A mixture of caprolactam monomer, lactam polymerizationinitiator and magnesium lactam polymerization catalyst is heated toabout 100° C. and is introduced into the mold and the temperatureresponse is recorded. The thermal trace starts an immediate rise due toheat contributed by the mold and the initial exotherm of the lactampolymerization. Before the temperature levels, a second sharp rise mayoccur, which is believed to be due to heat of crystallization and heatfrom the final stage of polymerization. The polymerization is consideredto be complete when the temperature reaches a maximum and starts tofall. The mass is quite solid and the molded article may now be removedfrom the mold. The reaction time is the time interval between theaddition of the reaction mixture to the mold and the attainment ofmaximum temperature. The overall reaction rate is considered to beproportional to the time for the temperature rise.

Tensile Strength: ASTM 1708 (units are in newton/meter²).

Elongation, Fail: ASTM 1708 (units are in percent).

Izod Impact Strength (notched): ASTM D256 (units are injoules/centimeter, J/cm).

EXAMPLE 1

Example 1 illustrates the preparation of a lactam polymerizationinitiator and a nylon block copolymer therefrom according to theinvention.

In a 2-liter, 4-neck flask fitted with a mechanical stirrer, condenser,N₂ inlet, dropping funnel, and thermocouple, 60.9 g terephthaloylchloride and 400 ml tetrahydrofuran (THF) are mixed, and then 60.6 gtriethylamine in 200 ml THF are added dropwise over a period of 1 hr. 10min., over which time the temperature increases from 15° to 21° C. Thismixture is stirred at 21° C. for 1 hr. 15 min., 33.9 g ε-caprolactam in100 ml THF is added dropwise over a period of 43 min., over which timethe temperature increases to 37° C., and then the mixture is stirred for1 hr., during which time the temperature drops to 23° C. At 23° C., 500g poly(oxypropylene) triamine having a number average molecular weightof 5000, available from Texaco Chemical Company, P.O. Box 430, Bellaire,Tex. 77401 under the tradename JEFFAMINE® T-5000, in 200 ml THF is addeddropwise over a period of 1 hr. 7 min., during which time thetemperature increases to 30° C. The product is then stirredapproximately 19 hrs., filtered, washed, stripped to constant weight,and dried.

To make a nylon block copolymer using a reaction injection moldingapparatus, a first mixture of 91.6 g. lactam polymerization initiator,prepared as above, and 158.4 g ε-caprolactam and a second mixture of 27g of a 1M caprolactam magnesium bromide solution in caprolactam and128.4 g ε-caprolactam are heated to 100° C., while stirring, and, whenhomogeneous, are deaerated for at least 10 minutes at approximately 1 mmvacuum. Both mixtures are then transferred to first and second 100° C.reservoirs and are pumped through a Kenics-type mixer into a 140° C.mold to form a 25 cm×25 cm×0.32 cm plaque. Reaction time and themechanical properties of the resulting nylon block copolymer plaque aregiven in Table 1.

EXAMPLE 2

Example 2 is also according to the invention but differs from Example 1in that the initiator lactam terminal groups are provided by2pyrrolidinone rather than s-caprolactam.

In a 1-liter, 4-neck flask fitted with a mechanical stirrer, condenser,N₂ inlet, dropping funnel, and thermocouple 24.4 g terephthaloylchloride and 160 ml THF are mixed, and then 24.2 g triethylamine in 80ml THF are added dropwise over a 1 hour period, over which time thetemperature increases from 19° to 23° C. This mixture is then stirredfor 1 hour at 23° C., and then 10.2 g 2-pyrrolidinone in 40 ml THF isadded dropwise over a 1 hour period, over which time the temperatureincreases to 33° C., and then is stirred for 1 hour, during which timethe temperature drops to 24° C. At 24° C., 200 g poly(oxypropylene)triamine, further described in Example 1, in 80 ml THF is added dropwiseover a 50 minute period, during which time the temperature increases to35° C. The product is then stirred for 2.5 hours, filtered, washed,stripped to constant weight, and dried.

To make a nylon block copolymer from the initiator formed in Example 2in the same apparatus as used in Example 1, the procedure of Example 1is followed, except that 90.3 g initiator and 109.7 g ε-caprolactam arecombined in the first reservoir; and 27 g of a 1M caprolactam magnesiumbromide solution in caprolactam and 178.4 g ε-caprolactam are combinedin the second. The mechanical properties of the resulting nylon blockcopolymer plaque are given in Table 1.

EXAMPLE 3

Example 3 is according to the invention and is prepared by the sameroute and using the same proportions as in Example 1 except that 50.8 gterephthaloyl chloride, 50.5 g triethylamine and 28.3 g ε-caprolactamare used to prepare the initiator and the polyamine ispoly(oxypropylene) diamine, having a number average molecular weight of4000, available under the tradename JEFFAMINE® D-4000. The nylon blockcopolymer plaque is prepared as in Example 1 and its mechanicalproperties are given in Table 1. The lower impact strength andelongation at fail, when compared to those of Examples 1 and 2, areattributed to the use of the diamine of Example 3 in place of thepolyamine of Examples 1 and 2.

EXAMPLE 4

Example 4, which illustrates the preparation of a nylon block copolymerby reacting the polyamine, the bis-acyllactam, and the lactam monomersimultaneously, is not according to the invention. The results of thisexample, when compared to those for the examples which are according tothe invention, illustrate the necessity for substantially forming thelactam polymerization initiator prior to polymerization of the lactammonomer, as is accomplished by the process of the invention.

To make a nylon block copolymer in the same apparatus as is used inExample 1, 79.9 g of the poly(oxypropylene)triamine (Jeffamine® T-5000),153 g ε-caprolactam, and 17.1 g isophthaloyl bis-acyllactam (added justprior to injection) are combined at 100° C. in the first reservoir, and27.9 g of a 1M solution of caprolactam magnesium bromide in caprolactamand 128.4 g ε-caprolactam are combined at 100° C. in the second. The twomixtures are then pumped into a 140° C. mold, as in Example 1. Reactiontime and the mechanical properties of the resulting nylon blockcopolymer plaque are given in Table 1.

EXAMPLE 5

Example 5, which illustrates the preparation of a nylon block copolymerby first reacting the bis-acyllactam and the polyamine at an elevatedtemperature prior to lactam polymerization but not by the reaction routeof the invention.

The nylon block copolymer of Example 5 is prepared substantially inaccordance with that described in Example 4, except that theisophthaloyl bis-acyllactam, poly(oxypropylene)triamine, andε-caprolactam in the first reservoir are heated for 4 hours at 100° C.and then degassed prior to injection. The results of this example, givenin Table 1, when compared to those for Examples 1 and 2, illustrate theimproved impact strength obtained when the nylon block copolymer isprepared according to the process of the invention.

                  TABLE I                                                         ______________________________________                                                          Elonga-  Izod                                               Tensile*          tion     Im-     Reaction                                   Example                                                                              Yield    Fail      Fail, %                                                                              pact**                                                                              Time, Sec.                             ______________________________________                                        1      4.9 × 10.sup.7                                                                   4.5 × 10.sup.7                                                                    79     6.63  100                                    2      5.3 × 10.sup.7                                                                   5.0 × 10.sup.7                                                                    160    5.62  --                                     3      5.1 × 10.sup.7                                                                   4.7 × 10.sup.7                                                                    29.3   1.30  --                                     4      --       0.87 × 10.sup.7                                                                   10.9   0.54  --                                     (Control)                                                                     5      6.0 × 10.sup.7                                                                   5.3 × 10.sup.7                                                                    150    1.82   74                                    (Control)                                                                     ______________________________________                                         *newton/meter.sup.2                                                           **(notched) joules/cm                                                    

In Table 1, the notation "---" indicates that the measurement was notmade.

We claim:
 1. The composition comprising:a lactam monomer; and the lactampolymerization initiator having at least two lactam terminal groups ofthe formula: ##STR12## wherein Q is a lactam residue containing a C₃-C₁₁ alkylene group and bonded to a carbonyl through the nitrogen atomof the lactam; A is an aliphatic or aromatic hydrocarbyl or hydrocarbylether group; m is 0 or 1; when m is 0, n is 0 or 1 and p is 1; when m is1, n is in the range of 1 to 3 and p=n; and an elastomeric backbonederived from a telechelic polyamine containing at least two primary orsecondary amine groups.
 2. The composition of claim 1 wherein thetelechelic polyamine is selected from the group consisting ofpolyoxyalkylene polyamines, oxyalkylene copolymer polyamines,polyalkadiene polyamines, alkadiene copolymer polyamines, polyalkenepolyamines, alkene copolymer polyamines, and combinations thereof. 3.The composition of claim 1 wherein at least 90 mole % of the aminegroups have been reacted to form the lactam terminal groups.
 4. Thecomposition of claim 1 wherein at least 95 mole % of the amine groupshave been reacted to form the lactam terminal groups.
 5. The compositionof claim 1 wherein m and n are
 1. 6. The composition of claim 4 whereinm and n are
 1. 7. The composition of claim 1 wherein m and n are 1 and Ais meta- or para-phenylene.
 8. The composition of claim 4 wherein m andn are 1 and A is meta- or para-phenylene.
 9. The composition of claim 1wherein the telechelic polyamine has a number average molecular weightgreater than about
 300. 10. The composition of claim 1 wherein thetelechelic polyamine has a number average molecular weight greater thanabout
 10000. 11. The composition of claim 1 wherein the telechelicpolyamine has at least three amine groups.
 12. The composition of claim3 wherein the telechelic polyamine has at least three amine groups. 13.The composition of claim 11 wherein m and n are 1 and A is meta- orpara-phenylene.
 14. The composition of claim 1 wherein A is a C₃ to C₈hydrocarbyl radical.
 15. The composition of claim 1 wherein A is ahydrocarbyl radical selected from the group consisting ofpara-phenylene, meta-phenylene, and --CH₂ --_(x), wherein x is in therange of 3 to
 8. 16. The composition of claim 1 additionally comprisinga substituted ammonium halide.
 17. The composition comprising:a lactammonomer; and a lactam polymerization initiator represented by theformula: ##STR13## wherein Z is a polyvalent radical derived from atelechelic polymine containing at least 2 primary or secondary aminegroups selected from the group consisting of polyoxyalkylene polyamines,oxyalkylene copolymer polyamines, polyalkadiene polyamines, alkadienecopolymer polyamines, polyalkene polyamines, alkene copolymerpolyamines, and combinations thereof; A is an aliphatic or aromatichydrocarbyl or hydrocarbyl ether group; Q is a lactam residue containinga C₃ to C₁₁ alkylene group; t is at least 1; m is 0 or 1, when m is 0, nis 0 or 1 and p is 1 and when m is 1, n is in the range of 1 to 3 andp=n.
 18. The composition of claim 17 wherein m and n are 1 and A ismeta-or para-phenylene.
 19. The composition of claim 17 wherein thetelechelic polyamine has a number average molecular weight of at leastabout
 300. 20. The composition of claim 17 wherein the telechelicpolyamine has a number average molecular weight of at least about 1000.21. The composition of claim 17 wherein the telechelic polyamine has atleast 3 primary or secondary amine groups.
 22. The composition of claim17 additionally comprising a substituted ammonium halide.
 23. Theprocess comprising: preparing a lactam polymerization initiator by:(a)complexing the acid halide groups of a polyfunctional acid halide with atertiary amine; (b) reacting at least one but less than all of thecomplexed acid halide groups with a lactam monomer represented by theformula ##STR14## where Y is a C₃ to C₁₁ alkylene group to replace thehalogen with a lactam residue and form an ammonium halide salt; (c)reacting at least 90 mole % of the remaining complexed acid halidegroups with a polyamine having at least 2 primary amine groups to formamine groups and ammonium halide salt; (d) removing the ammonium halidesalt and obtaining the lactam polymerization initiator; and reacting thelactam polymerization initiator with lactam monomer in the presence of alactam polymerization catalyst to form a nylong block copolymer havingblock linkages of the formula; ##STR15## wherein Y is a C₃ -C₁₁ alkylenegroup, A is an aromatic or aliphatic hydrocarbyl or hydrocarbyl ethergroup, and m is 0 or 1; when m is 0, n is 0 or 1 and p is 1; and when mis 1, n is in the range of 1 to 3 and p=n.
 24. The process of claim 23wherein about 50 mole % of the halogen groups of the complexed acidhalide are replaced with a lactam residue in step (b).
 25. The nylonblock copolymer formed by the process of claim
 23. 26. A nylon blockcopolymer, comprising soft and hard segments, wherein the hard segmentsconsist essentially of segments of the formula: ##STR16## wherein q=4 to300, and Y is a C₃ -C₁₁ alkylene group and the soft segments contributea T_(g) of less than 0° C.; and wherein the soft and hard segments arelinked by segments consisting essentially of: ##STR17## wherein Y is aC₃ -C₁₁ alkylene group, A is an aromatic or aliphatic hydrocarbyl orhydrocarbyl ether group, and m is 0 or 1; when m is 0, n is 0 or 1 and pis 1; and when m is 1, n is in the range of 1 to 3 and p=n.
 27. Theprocess of claim 23, wherein the lactam polymerization step issubstantially complete in less than about 3 minutes.
 28. The process ofclaim 23, wherein the lactam polymerization step is substantiallycomplete in less than about 1 minute.
 29. The process of claim 23wherein, prior to performing the lactam polymerization step, at least95% of the lactam terminal groups of the initiator are of the formula:##STR18## wherein A is an aromatic or aliphatic hydrocarbyl orhydrocarbyl ether group, Q is a lactam residue containing a C₃ to C₁₁alkylene group, and m is 0 or 1; when m is 0, n is 0 or 1 and when m is1, n is in the range of 1 to 3.